The art of manufacturing glass containers by the so called press and blow method in a Hartford I.S. machine is well known. In accordance with this method glass gobs or charges are fed from a source into an upwardly open blank mold, which blank mold may comprise two molds in a typical double gob operation, and each of which blank molds are subsequently closed at the top by a baffle. Pressing plungers then move upwardly into the blank molds to force the molten glass gob into each blank mold, and into the associated neck ring mold, after which the plunger is withdrawn and the blank mold and the baffle removed, so that the neck ring mold can invert the parison from the blank to a blow mold station in a typical Hartford I.S. glassware forming machine. The glass gob or charge is supported by the upper end of the plunger during loading, and once the baffle has been moved into place the gob or charge is then pressed by upward movement of the plunger within the blank mold to form the glass by molding contact with the internal walls of the inverted blank mold. A portion of the glass charge is displaced downwardly into molding contact with the walls of the neck ring mold, and its associated thimble. The plunger is then retracted after the pressing stroke, to a level below that at which the plunger first contacts the glass charge, in order to allow clearance for movement of the neck ring mold, and the associated parison, in a curved path to an adjacent blow mold station at which the parison is further formed in a final blowing step.
In double gob operation pursuant to this pressing of the parison, plunger mechanisms of different types must occasionally be removed and replaced when glassware articles of different size and shape are to be formed. That is, the center distances may vary, or a pressing plunger mechanism may have to be replaced with a blow and blow plunger mechanism.
The present invention has as its primary object an improved floating plunger mechanism wherein a bottom or base plate is provided on a vertically adjustable jack screw, which bottom plate not only provides a convenient manifold for connecting the fluid operated components of the plunger mechanism to the valve block and timing drum characteristic of the I.S. machine, but the bottom or base plate also includes a flat upper surface, without protrusions, for convenience in assemblying the plunger mechanism therewith. The bottom or base plate is also floating, in that it is capable of horizontal movement to accommodate slight horizontal movement of the plunger mechanism as required in order to align the vertically movable plungers with their associated blank molds. Further, the plunger cooling tube is also free to float slightly in the plunger mechanism itself.